checkout -m: fix read-tree invocation

When we updated "read-tree -m -u" to be careful about not
removing untracked working tree files, we broke "checkout -m" to
switch between branches.

Signed-off-by: Junio C Hamano <[email protected]>

Author: Junio C Hamano

git-checkout.sh

@@ -150,8 +150,7 @@ else
 	# Match the index to the working tree, and do a three-way.
     	git diff-files --name-only | git update-index --remove --stdin &&
 	work=`git write-tree` &&
-	git read-tree --reset $new &&
-	git checkout-index -f -u -q -a &&
+	git read-tree --reset -u $new &&
 	git read-tree -m -u --aggressive $old $new $work || exit
 
 	if result=`git write-tree 2>/dev/null`

t/t7201-co.sh

@@ -0,0 +1,72 @@
+#!/bin/sh
+#
+# Copyright (c) 2006 Junio C Hamano
+#
+
+test_description='git-checkout tests.'
+
+. ./test-lib.sh
+
+fill () {
+	for i
+	do
+		echo "$i"
+	done
+}
+
+test_expect_success setup '
+
+	fill 1 2 3 4 5 >one &&
+	fill a b c d e >two &&
+	git add one two &&
+	git commit -m "Initial A one, A two" &&
+
+	git checkout -b side &&
+	fill 1 2 3 >one &&
+	fill A B C D E >three &&
+	rm -f two &&
+	git update-index --add --remove one two three &&
+	git commit -m "Side M one, D two, A three" &&
+
+	git checkout master
+'
+
+test_expect_success "checkout with dirty tree without -m" '
+
+	fill 0 1 2 3 4 5 >one &&
+	if git checkout side
+	then
+		echo Not happy
+		false
+	else
+		echo "happy - failed correctly"
+	fi
+
+'
+
+test_expect_success "checkout -m with dirty tree" '
+
+	git checkout -f master &&
+	git clean &&
+
+	fill 0 1 2 3 4 5 >one &&
+	git checkout -m side &&
+
+	fill "  master" "* side" >expect.branch &&
+	git branch >current.branch &&
+	diff expect.branch current.branch &&
+
+	fill "M	one" "A	three" "D	two" >expect.master &&
+	git diff --name-status master >current.master &&
+	diff expect.master current.master &&
+
+	fill "M	one" >expect.side &&
+	git diff --name-status side >current.side &&
+	diff expect.side current.side &&
+
+	: >expect.index &&
+	git diff --cached >current.index &&
+	diff expect.index current.index
+'
+
+test_done